A federal jury handed Whitewater independent counsel Kenneth W. Starr a decisive victory here today by convicting two of President Clinton's former business partners and Gov. Jim Guy Tucker (D) of nearly all the fraud and conspiracy charges Starr lodged against them 10 months ago.

Tucker, now in his second term, promptly announced his resignation at a news conference in the state Capitol, saying he will leave office by July 15.

The jury of nine women and three men ended the three-month-long trial by convicting James B. McDougal, who once owned a Little Rock savings and loan, of 18 charges of conspiracy and fraud.

McDougal's former wife, Susan, who some courtroom observers believed would be acquitted because of her lesser role in the fraudulent transactions, was convicted on all four charges against her, which included mail fraud and making false financial entries and statements. Two jurors said later that Clinton's testimony for the defense had no bearing on their decision to convict his former business partners.

Tucker, 52, who succeeded Clinton as governor, was convicted of conspiracy and mail fraud in real estate development schemes that eventually helped destroy McDougal's savings and loan. "I'm sure they tried to do the right thing," Tucker said of the jurors. "As it happens, they just did the wrong thing."

Clinton's close relationship with the McDougals during his years as Arkansas's governor has been a continuing source of political embarrassment over the past four years, and the jury's decision only exacerbates that. At the White House, Clinton told reporters he was saddened by the convictions of his longtime Arkansas friends, who now face years in prison and fines amounting to millions of dollars.The defense had called Clinton to testify in hopes he would damage the credibility of the chief prosecution witness.

The convictions could not have been more timely or cumulatively powerful for Starr, a Republican who has been criticized for his conduct of the investigation, especially by Democratic partisans. The result also represented a vindication for a sometimes risky prosecution strategy of drowning the jury with documentary evidence, in this case more than 600 exhibits.

By contrast, jurors said, the defense presented almost no case, other than the testimony of the president and James McDougal. "I can't understand why they rested so quickly," said one alternate juror. The panel deliberated for eight days before reaching the verdicts.

In Washington, a beaming Starr told reporters he was "obviously gratified" by the trial's outcome and alluded to a home-court advantage that never materialized for the defendants, calling the convictions "a tribute to the people of Arkansas."

"What now? We move forward," Starr said.

The subtext of the trial, so strongly flavored by Arkansas politics and the election-year struggle between national Democrats and Republicans, was the contest between Starr and the Clinton White House. As independent counsel, Starr had broad prosecutorial powers and grand juries to help him unravel the go-go real estate deals that transformed Little Rock while Clinton was governor in the mid-1980s.

Clinton faced no criminal charges in this trial, but the White House clearly did not relish the idea of a jury's branding his Whitewater partners as crooks at the very moment the president geared up his reelection campaign.

Although the trial centered on a complex loan-swapping scheme, it touched on the Whitewater real estate development, in which the Clintons and McDougals were partners. Prosecution witness David Hale testified that Clinton, as governor, asked him to approve an illegal $300,000 loan to Susan McDougal. About $50,000 of the proceeds of that loan went into a Whitewater account.

Clinton, in videotaped testimony played in court, heatedly denied that he urged Hale to make the loan. Risa Gayle Briggs, a 41-year schoolteacher who sat on the jury, said the panel did not focus on Clinton's testimony, although she called him a "very credible" witness. "His name was brought up during the deliberations maybe once in passing," she said. "The president's testimony had nothing to do with the transactions we were homing in on and discussing.

"We had enough credible witnesses that we didn't have to rely on Clinton or Hale," she said. "We drew diagrams, we story-webbed it out, we did a time line, we went over everything with a fine-tooth comb."

Said another juror, Janice R. Greer: "It was the documents we went with. The documents told me more than the testimony did."

The verdicts were returned late in the day in a windowless courtroom thick with tension and heat in a spring swelter. The defendants and their lawyers hugged and shook hands and clapped one another on the back before the jury returned, but became visibly tense when the clerk read out the 30 verdicts in a monotone.

Tucker scowled as she pronounced him guilty of conspiracy, the most serious charge he faced. McDougal remained impassive, his left hand cradling his chin.

Like the Whitewater hearings conducted by the special Senate committee for the past two years, the lengthy trial was a step backward in time to a period when financial institutions like McDougal's Madison Guaranty became risk-takers venturing into new enterprises, especially large-scale real estate development.

Prosecutors portrayed McDougal as the mastermind of several schemes involving dummy corporations, insider deals and false filings to regulators to increase his personal profits and those of his co-conspirators. The prosecution claimed that the McDougals, Tucker and Hale, who owned a lending firm backed by Small Business Administration funds, used Hale's firm as a source of illegal loans.

There was agreement among defense counsel and prosecutors alike that McDougal fared poorly on the stand, contradicting earlier statements and failing to recall key episodes. Ernest Williams, a 37-year-old alternate juror, said, "Jim McDougal messed himself up real bad when he got on the stand. . . . There were things he could remember from 30 years ago but not from five or 10 years ago . . .

"I think the best thing would have been for him to stay at the table with his lawyer."

Others on the defense team added it may have been a mistake for Tucker not to testify in his defense. They also criticized his attorney's closing argument as weak.

Though he sometimes seemed to meander in talking to jurors, prosecutor W. Ray Jahn constructed a solid documentary case against the three defendants, bolstering the testimony of his witnesses with a lengthy paper trail.

Jahn, a big bear of a man with sandy hair and a mustache who favored striped ties and suspenders, ran his side of the case ferociously, setting up a war room for the prosecution team in the bowels of the federal building across the street from the U.S. District Court building within sight of the Arkansas statehouse.

Inside the locked room, inspirational posters were hung on cinder-block walls reading "Confusion to our enemies" and "Once more into the breach, dear friends," symbols of the zeal with which Starr's subordinates brought to the trial.

"It's crime, not politics," Jahn said in an interview on the first full day of jury deliberations.

Jahn is an expert prosecutor of bank fraud trials, having conducted his first 20 years ago as an assistant U.S. attorney in San Antonio. He said he was fully confident that the Little Rock jury could sift through the complicated transactions that McDougal engineered while at the helm of Madison Guaranty.

"The issue is how do you simplify it so the hearer understands," Jahn said. "If you can show them the badges of fraud, they'll understand."

"They paid attention," Jahn added. "This jury stayed with it all the way through."

McDougal, 55, faces up to 84 years in prison and $4.5 million in fines. Susan McDougal faces as much as 17 years in prison and a $1 million fine. Tucker could receive up to 10 years in prison and a $500,000 fine.

At a news conference at the state Capitol, Tucker, looking visibly shaken, said: "Although I am innocent of all charges made, I must accept the verdict of the jury while I appeal. But I cannot, and should not, allow our people, or our state, bear any part of that burden."

Tucker will most likely be succeeded by Lt. Gov. Mike Huckabee, a Republican who is currently running for the U.S. Senate seat being vacated by retiring Sen. David Pryor (D).

At least nine other sitting governors have been indicted while in office. Among them was Marvin Mandel, the governor of Maryland who served 14 months in prison for mail fraud and bribery, and Guy Hunt, governor of Alabama, who was convicted of violating a federal ethics law.

Republican members of Congress said today's verdicts legitimize the various inquiries into Whitewater. Sen. Alfonse M. D'Amato (R-N.Y.), who heads a Senate committee probing Whitewater, said the verdicts show that "there really is substance to the Whitewater investigation, as opposed to it being challenged as it has, as just being partisan without any substance. I think the jury has certainly demonstrated that this is real."

Rep. Jim Leach (R-Iowa), who chairs the House Banking Committee that has investigated Whitewater, said on CNN: "I have never suggested a legal context needed to be applied to the president. But in terms of the ethical aspects of this whole Whitewater circumstance, it's going to be very serious for him."

Staff writer Serge Kovaleski in Washington contributed to this report.